Journal article

Publication year: 2003

Pages: 115-122

Journal: Acta ethologica

Volume number: 5

Issue number: 2

DOI Link: https://doi.org/10.1007/s10211-003-0074-9

Publisher: Springer

Abstract: 

When resources are limited, life-history theory predicts that long-lived animals should allocate available resources to body maintenance rather than to reproduction in order to maximise their lifetime reproductive success. In the present study, we estimated physiological stress in a small procellariiform seabird, the Wilson's storm-petrel Oceanites oceanicus, as a means of understanding how limited resources are partitioned between provisioning parents and their chicks. We analysed adrenocortical activity of Wilson's storm-petrels during the breeding season by measuring glucocorticoid (GC) excretion, using an enzyme immunoassay measuring tetrahydrocorticosterone concentrations in extracts of faeces and urine of chicks and adults. Faecal GC measures were negatively correlated with chick body condition, suggesting that measures of tetrahydrocorticosterone in faeces and urine can be used to assess adrenal activity characteristic for physiological stress in Wilson's storm-petrels. In the breeding season of 1999, the colony was subject to low food availability, and the faecal and urine GC levels of chicks were elevated during these months of chronic starvation. In contrast, adults did not show elevated GC levels. The data thus suggest that Wilson's storm-petrels respond to unfavourable conditions by maintaining their own body condition and reducing provisioning of food to their chicks.When resources are limited, life-history theory predicts that long-lived animals should allocate available resources to body maintenance rather than to reproduction in order to maximise their lifetime reproductive success. In the present study, we estimated physiological stress in a small procellariiform seabird, the Wilson's storm-petrel Oceanites oceanicus, as a means of understanding how limited resources are partitioned between provisioning parents and their chicks. We analysed adrenocortical activity of Wilson's storm-petrels during the breeding season by measuring glucocorticoid (GC) excretion, using an enzyme immunoassay measuring tetrahydrocorticosterone concentrations in extracts of faeces and urine of chicks and adults. Faecal GC measures were negatively correlated with chick body condition, suggesting that measures of tetrahydrocorticosterone in faeces and urine can be used to assess adrenal activity characteristic for physiological stress in Wilson's storm-petrels. In the breeding season of 1999, the colony was subject to low food availability, and the faecal and urine GC levels of chicks were elevated during these months of chronic starvation. In contrast, adults did not show elevated GC levels. The data thus suggest that Wilson's storm-petrels respond to unfavourable conditions by maintaining their own body condition and reducing provisioning of food to their chicks.

Harvard Citation style: Quillfeldt, P. and Möstl, E. (2003) Resource allocation in Wilson's storm-petrels Oceanites oceanicus determined by measurement of glucocorticoid excretion, Acta ethologica, 5(2), pp. 115-122. https://doi.org/10.1007/s10211-003-0074-9

APA Citation style: Quillfeldt, P., & Möstl, E. (2003). Resource allocation in Wilson's storm-petrels Oceanites oceanicus determined by measurement of glucocorticoid excretion. Acta ethologica. 5(2), 115-122. https://doi.org/10.1007/s10211-003-0074-9